Provided is a method for improving salt tolerance of a plant so as to enable the cultivation of the plant in a high salt concentration environment. The present invention relates to: a method for improving salt tolerance of a plant, said method comprising regulating or inhibiting the function of proline-rich extensin-like receptor kinase 13 (PERK13) of a plant； the method for improving salt tolerance of a plant as described above, wherein the roots of the plant are brought into contact with a PERK13 antagonist； any of the methods for improving salt tolerance as described above, wherein the antagonist is one or more kinds of microorganisms or secretion(s) of the same； and the method for improving salt tolerance of a plant as described above, wherein the function of PERK13 is regulated by regulating the expression of a PERK13 gene, or the function of PERK13 is inhibited by inhibiting the expression of a PERK13 gene.
